Rotary switch



0a. 7, 1969 v L. H. ELLIOTT 3,471,658

ROTARY SWITCH 2 Sheets-Sheet 1 Filed Oct. 30. 1968 5 1 Wm 21 4 F a w P v M a y M Z w 5 J a 7, 5. M y 7 m2 m 1 firm J w ww w? a HIS grwozawz'yi L. H. ELLIOTT Oct. 7, 1 969 ROTARY SWITCH 2 Sheets-Sheet 2 Filed Oct. 30 1968 0125x7015 fgnzz A. EUz'occ.

3,471,658 ROTARY SWITCH Lynn H. Elliott, Addison, Tex., assignor to All Plastics U.S. Cl. 200-8 15 Claims ABSTRACT OF THE DISCLOSURE I disclose a rotary switch unit comprising a support, at least one pair of spring arms spacedly mounted on said support and having respective electrical contacts thereon, a rotor rotatably mounted on said support and extending generally between said spring arms, a through contact on said rotor and disposed to engage said spring arm contacts at a given rotational position of said rotor, said spring arms being shaped for hearing engagement of their contacts with said rotor contact when said rotor contact is juxtaposed thereto and for bearing engagement with diametrically opposed arcuate surfaces of said rotor to restrain movement of said rotor when said rotor contact is angularly displaced relative to spring arm contacts.

The present invention relates to a rotary switch and more particularly to a rotary limit switch for use with valve operators and other rotary equipment. Specifically, the invention is concerned with a switch of the character described in which the contacts can be readily and conveniently changed between normally closed and normally opened conditions.

Although my invention is described primarily with reference to valve operators, it will be obvious from the following description that my rotary switch is not so limited, but is capable of use in many diverse applications.

There are a number of known switches, the contacts of which can be actuated by rotary movement. Many of these switches have been employed as limit switches for valve operators and other types of mechanisms subject to rotary movement. One or more such switches can be employed in a given application, depending upon the number of circuits which are required to be opened or closed at the limits of rotary movement or at predetermined points between such limits.

Insofar as I am aware, however, none of these prior rotary switches can be readily changed from a normally opened to a normally closed position, or vice versa, depending upon the application of the circuits associated with the valve operator or the like. In particular, it has been difiicult to provide a multiple contact or ganged rotary switch with such means. Conventional switches are also diflicult to adjust as to angular displacement relative to driving means for the switch, without shock hazards resulting from inadvertent physical contact with switch components or electric circuits coupled to the switch. Prior ganged switches, moreover, cannot be readily coupled end-to-end for stacking purposes, or used in parallel in difiering angular dispositions relative to one another and to the aforementioned valve operator or the like.

I am aware of course that previous switches have been provided with reversible contacts. For the most part these prior switches are recilinear in construction and are typified by Hyink et a1. 3,129,304; Haydu 3,238,341; and Birch 2,924,685. The patented switches are of the solenoid operated or relay variety, and moreover, entirely different contact configuration and extensive disassem-bly of the switch is required for contact reversals.

A previous type of ganged switch is typified by South 2,945,096 and Conradty 2,335,388. These patented switches are utilized for commutating or programming United States Patent 3,471,658 Patented Oct. 7, 1969 See purposes. Although their contacts are angularly adjustable to meet the obvious applicational requirements of the switches, these prior switches cannot be readily adjusted between normally opened and normally closed conditions. Thus, prior switches of this type are not readily adaptable for use as rotary limit switches or in other applications of my novel switch.

I overcome these disadvantages of the prior art by providing a rotary switch and particularly a multiple contact or ganged rotary switch the contacts of which can be readily and conveniently changed between normally opened and normally closed positions. My novel switch in its ganged arrangement can be stacked end-to-end with similar ganged switches to provide virtually an unlimited number of contacts per rotary switch. Alternatively, a number of my novel switches can be employed in parallel, and means forming part of the switch structure facilitates angular disposition or displacement of one of these switches relative to another. With increasing automation taking place, the use of the large numbers of switch contacts thus made available is of considerable importance to the valve control industry and to any industry utilizing rotary mechanisms or drives. In constructing my novel rotary switch, I provide novel means for preventing electrical contact between a screw driver or other tool and any of the switch elements, when the rotary switch is adjusted relative to its drive, for example.

I accomplish these desirable results by providing a rotary switch unit comprising a support, a pair of spring arms spacedly mounted on said support and having respective electrical contacts thereon, a rotor rotatably mounted on said support and extending generally between said spring arms, a through contact on said rotor and disposed to engage said spring arm contacts at a given rotational position of said rotor, said spring arms being shaped for bearing engagement of their contacts with said rotor contact when said rotor contact is juxtaposed thereto and for bearing engagement with diametrically opposed arcuate surfaces of said rotor to restrain movement of said rotor when said rotor contact is angularly displaced relative to said spring arm contacts.

I also provide a similar rotary switch wherein keying means are formed in each end of said rotor for connection of said switch unit to at least one of the group consisting of driving means therefor and another switch unit.

I also provide a similar rotary switch wherein said spring arms are bent and otherwise shaped so that reversal thereof changes said switch between normally opened and normally closed conditions.

I also provide a similar rotary switch wherein the contacting surfaces of said rotor contact are disposed respectively on diametrically opposed fiat surfaces separated by said arcuate surfaces by ridges extending longitudinally of said rotor so that said bearing engagement of said spring arm contacts with said arcuate surfaces causes said contacts to snap over said ridges and into and out of engagement with said rotor contact.

I also desirably provide a rotary switch unit comprising a pair of spaced end plates, spaced supporting members extending between said end plates, a rotor rotatably mounted adjacent its ends upon said end plates and extending generally between said supporting members, a plurality of spring arms mounted on each of said supporting members in spaced relation along the length thereof and aligned transversely and respectively with the spring arms of the other of said supporting members, said rotor being fabricated from an insulating material and having a plurality of through contacts spaced therealong in transverse alignment with said spring arms respectively, some of said spring arms being bent in a clockwise direction and others in a counterclockwise direction relative to said rotor so that at a given position of said rotor some of said spring arms are in normally opened condition and others of said spring arms are in normally closed condition relative to said rotor contacts.

I also provide a similar rotary switch wherein said end plates are provided with aligned aperture means for insertion of an adjustment tool or the like, and a tubular extension is secured to each of said end plates in communication and in alignment with said aperture means so that said tool cannot be angulated to engage electrical components of said switch upon insertion through said aperture means.

During the foregoing discussion, various objects, features and advantages of the invention have been set forth. These and other objects, features and advantages of the invention together with structural details thereof will be elaborated upon duIing the forthcoming description of presently preferred embodiments of the invention and presently preferred methods of practicing the same.

In the accompanying drawings I have shown certain presently preferred embodiments of the invention and have illustrated certain presently preferred methods of practicing the same, wherein:

FIGURE 1 is an isometric View of one arrangement of my novel rotary switch shown exemplarily in ganged formation; 1

FIGURE 2 is a bottom plan view of the switch shown shown in FIGURE 1. FIGURE 2 also shows exemplary means in accordance with my invention for stacking two or more of the switch units illustrated herein;

FIGURE 3 is a cross sectional view of the switch as shown in FIGURE 1 and taken along reference line III III thereof;

FIGURE 4 is another cross sectional view of the switch as shown in FIGURE 1 and taken along reference line IV-IV thereof;

FIGURE 5 is an enlarged, isometric view of a keying member used for stacking the switch modules of FIG- URE 2;

FIGURE 6 is an elevational view showing usage of two or more of my novel switch units; and

FIGURE 7 is a top plan view of the apparatus as shown in FIGURE 6.

Referring now to the drawings and initially to FIG- URES l and 2 thereof an exemplary form of my rotary switch 10 includes a pair of spaced supporting plates 12, 14 which are maintained in their spaced relation by rods 16, 18. Desirably, portions of the rods 16, 18 can be molded integrally with the end plates 12, 14 respectively and solvent welded or otherwise joined at their projecting ends to form the assembled switch 10 shown in FIG- URE 1.

A rotor 20 is fabricated chiefly from a suitable electrically insulating material and is rotatably mounted adjacent its ends in the end plates 12, 14 respectively. A number of radial flanges 22 are spaced along the length of the rotor 20. The end flanges 22a position the rotor 20 between the spaced end plates 12, 14. The remainder of the flanges 22 divide the rotor 20 into discrete contact sections corresponding to the switch compartments segregated by partitions 24 spaced along the length of spring arm supporting or retaining members 26.

The rotor 20 is further furnished with a plurality of through or double-ended contacts 28 extending through the rotor as shown in FIGURES 3 and 4 and positioned respectively in the rotor areas between the rotor flanges 22. Desirably, the rotor contacts 28 are provided with rounded outer ends or contact surfaces 30.

Each of the supporting members 26 is provided with a series of stationary quick-connect contact blades 32 secured thereto by mounting screws 34. The screws 34 also secure a like number of contact or spring arms 36, 37 of the leaf spring variety in this example. Each of the spring arms 36, 37 is provided with a rounded electrical contact 38 or 40.

As better shown in FIGURES 3 and 4 the switch rotor 20 is desirably provided with a pair of diametrically opposite flat surfaces 42 with intervening arcuate surfaces 44, all of which extend longitudinally of the rotor 20. In the position of the rotor 20- as shown in FIGURES 3 and 4 the contacts 38 on spring arms 36 are normally opened while the contacts 40 on spring arms 37 are normally closed, as they are electrically connected through the intervening and associated rotor contacts 28. With the use spring arms 36, 37 it will be seen from FIGURE 4 that a modified over-center action results as the normally closed contacts 40 traverse or wipe across the rotor contacts 30 as the rotor 20 is resolved through This overcenter action aids in making and breaking the respective switch contacts. However, the spring contacts 40 can be centered on the rotor contacts 30 in the illustrated rotor position by means of the frictional engagement of the normally opened contacts 38 (FIGURE 3) with the acruate rotor surfaces 44.

Making and breaking of the respective switch contacts is also facilitated by longitudinal ridges 46 separating the flat and rounded surfaces 42, 44 of the rotor 20. As the rotor 20 turns the spring arm contacts 38 or 40 snap over the longitudinal ridges '46 and pass directly into or out of engagement as the case may be with the rotor contacts 30. That is to say, the spring arm contacts 38 or 40 do not engage the flat rotor surfaces 42 and particularly those portions of the flat surfaces which lie between either side of the rotor contacts 30 and the longitudinal ridges 46.

In the operation of the switch 10, the rotor 20 can be moved in either direction of rotation as denoted by doubleheaded arrow 48 (FIGURE 1). A quarter turn displacement of the rotor 20, as by a known Geneva type gear train denoted very generally at reference character 50, is suificient to close the normally opened contacts 38 (FIGURE 3) and to open the normally closed contacts 40 (FIGURE 4). Obviously, the entire switch unit 10 can be angularly displaced relative to the gear unit 50 or other rotating means for the rotor 20 so that the normally opened contacts 30 become normally closed and the contacts 40 become normally opened.

For purposes of coupling the switch unit 10 to the driving means 50 each end of the rotor 20 desirably is provided with a keying slot 52. A key or pin is mounted on output shaft 54 of the driving means 50 for insertion into the rotor shaft 20 to key the rotor to the output shaft 54. On the other hand two or more of the rotary switches can be joined by means of keying members 56 (FIGURE 5) inserted into their respective rotor slots. To ensure co-axial alignment of the rotor 20 and shafts 54, the lots 52 and keying member 56 are provided with central arcuate contours 58. Turning of the switch unit support structure including the end plates 12, 14 relative to the driving means 50 is prevented by means of pins and holes 60, 61 formed on each end plate.

In a similar manner successive switch modules, which are substantially identical to the switch unit 10 can be joined to the other end of the switch unit 10 as illustrated in FIGURE 2. For example, end plate 14 of a succeeding switch unit 10a can be joined to end plate 12 of switch unit 10 by the aforementioned pins and holes 60, 61. The adjacent rotor ends can be keyed together by the keying member 56 in the manner described above.

In the switch unit 10 of FIGURES l and 2, three of the switch modules 11 are shown with their leaf spring contacts 40 in normally closed position (FIGURE 4) while two such switch modules have their contacts 38 in normally opened condition (FIGURE 3). However, the numbers of switch modules in each group of normally opened or normally closed modules can be readily changed. This is accomplished by removing the mounting screws 34 of one or more of the switch modules 11 together with their stationary contact blades 32 and spring arms 36 or 37. The spring arms 36 or 37 are merely inverted or positionally reversed so that the position of the leaf spring 36 is then assumed by the leaf spring 37 or vice versa as desired.

In many applications, the driving means 50 for the switch units or unit is provided with adjustment means, such as screw 62, whereby the movements of the output shaft 54 can be synchronized with associated equipment or with the desired timed operation of circuits controlled by the switch unit 10. To permit such adjustments to be safely made while the switch unit 10 is in operation or without otherwise de-energizing the circuits (not shown) coupled thereto, I provide means for affording access to the adjustment screw 62 without the possibility of accidental contact with those components of the switch unit 10 which may carry hazardous electrical potentials or which may be shorted out by a tool used to make such adjustment. In furtherance of this purpose each of the end plates 12, 14 are provided with a tubular extension 64 or 66. Aperture means in the end plates 12, 14 including passages 68 through the tubular extension 64, 66 are aligned with one another and with the adjustment screw 62. As a result, a screw driver or other suitable tool having requisite shank length can be inserted through the tubular extension openings 68 in order to effect such adjustment of the screw 62 from the opposite end of the switch unit 10. The passages 68 of the tubular extensions 64, 66 can be sized to prevent the insertion of a screw driver or other tool having an oversized blade and also to prevent angulation of the screw driver and inadvertent contact with one or more of the switch components.

As show in FIGURE 1 the tubular extension 64, 66 need not be continuous and desirably terminate short of the midsection of the switch unit 10. The tubular extension 64, 66 can be made continuous, if desired; however, the gap therebetween merely avoids the necessity of carefully sizing the free ends of the tubular extensions 64, 66. Naturally, the gap 70 is of sufficient size to permit any substantial angulation of the tool inserted through the tubular extension 64 or any avoidance of the adjacent end of the tubular extension 66.

If desired, the driving means 50 can be a suitable gearing train such that almost any desired mechanical movement can be translated into a quarter turn of the switch unit rotor 20. For example, the driving means 50 can be a digital gearing unit of the Geneva type and associated with a valve operator or similar rotary mechanism. The gear unit 50, then, can be arranged in a known manner to translate an anticipated number of valve operator turns into a quarter turn of the switch unit 10.

It is also contemplated, as set forth in FIGURES 6 and 7 that two or more switch units 10 can be connected in parallel fashion through separate driving means 50 therefor to a single valve operator represented by output shaft 72. With this disclosed arrangement, numbers of electric circuits can be opened and/ or closed at the fully opened and closed positions (rotary switches 10a and 10d of FIGURE 7) of the associated valves and also at intermediate valve positions, for example 10% and 80% open (rotary switches 10b and 100 respectively).

With this arrangement a fully automated manufacturing process or the like can be controlled from the opening and closing movements of a single valve or series of such valves. Other assemblages of the rotary switches 10 can be employed as dictated by other applications of the invention.

The relative positions of the switch rotors 20 of FIGURE 7 are denoted by their end slots 52, while arrows 74 show the relative orientations of the switch housings or supports including the end plates 12. Of course dilferent positions and orientations can be selected as desired. The normally opened or closed conditions of the various contacts of the switches 10a, 10b, 10c, 10d are shown by the schematic representations of contacts 30, 38, 40 in FIGURE 7.

From the foregoing it will be apparent that novel and efiicient forms of rotary switches have been described herein. While I have shown and described certain presently preferred embodiments of the invention and have illustrated certain presently preferred methods of practicing the same, it is to be distinctly understood that the invention is not limited thereto but may be variously embodied and practiced within the scope of the following claims.

I claim:

1. A rotary switch unit comprising a support, at least one pair of spring arms spacedly mounted on said support and having respective electrical contacts thereon, a rotor rotatably mounted on said support and extending generally between said spring arms, a through contact on said rotor and disposed to engage said spring arm contacts at a given rotational position of said rotor, said spring arms being shaped for hearing engagement of their contacts with said rotor contact when said rotor contact is juxtaposed thereto and for bearing engagement with diametrically opposed arcuate surfaces of said rotor to restrain movement of said rotor when said rotor contact is angularly displaced relative to spring arm contacts.

2. The combination according to claim 1 wherein said spring arms are bent and otherwise shaped so that reversal thereof changes said switch between normally opened and normally closed conditions.

3. The combination according to claim 1 wherein the contacting surfaces of said rotor are disposed relatively on diametrically opposed flat surfaces separated by said arcuate surfaces by ridges extending longitudinally of said rotor so that said bearing engagement of said spring arm contacts with said arcuate surfaces causes said contacts to snap over said ridges and into and out of engagement with said rotor contact.

4. The combination according to claim 1 wherein said support includes a pair of spaced end plates, a pair of spaced arm-retaining members extend between said end plates, a plurality of the spring arms are mounted upon each of said retaining members in transverse alignment with the spring arms on the other of said retaining members, said rotor is rotatably mounted on said end plates at a position generally between said retaining members and the spring arms associated therewith, and a like plurality of rotor contacts are mounted on said rotor for juxtaposition between transversely aligned pairs of said spring arm contacts.

5. The combination according to claim 4 wherein said rotor contacts are mounted in angular alignment, and at least one aligned pair of the spring arms are bent in a clockwise direction of said rotor and the remainder of said aligned pairs are bent in a counterclockwise direction of said rotor so that for a given rotor position said clockwise contacts are normally opened and said counterclock* wise contacts are normally closed.

6. The combination according to claim 5 wherein said clockwise and said counterclockwise spring arms are shaped so that reversal thereof changes their associated contacts between normally opened and normally closed conditions relative to a given position of said rotor contacts.

7. The combination according to claim 4 wherein said spring arms are separated by partition walls spacedly secured to each of said retaining members in transverse alignment with the partition walls of the other of said retaining members and contact dividing flanges are secured to said rotor in alignment with said partition walls respectively.

8. The combination according to claim 4 wherein keying means are formed in each end of said rotor and on the outer surfaces of said end plates for connection of said switch unit to at least one of the group consisting of driving means therefor and another switch unit.

9. The combination according to claim 4 wherein driving means having adjustment means are coupled to said switch unit, said end plates have aperture means in alignment with said adjustment means, and tubular extensions are secured to said end plates in communication with said aperture means, said extensions extending inwardly of said end plates to prevent contact of the switch components by a tool inserted through said aperture means for engagement with said adjustment means.

10. The combination according to claim 9 wherein all of said spring arms are shaped identically so that reversal of any aligned pair of said spring arms changes said spring arms between said normally opened and normally closed conditions.

11.The combination according to claim 1 wherein keying means are formed in each end of said rotor for connection of said switch unit to at least one of the group consisting of driving means therefor and another switch unit.

12. A rotary switch unit comprising a pair of spaced end plates, spaced supporting members extending between said end plates, a rotor rotatably mounted at its ends upon said end plates and extending generally between said supporting members, a plurality of spring arms mounted on each of said supporting members in spaced relation along the length thereof and aligned transversely and respectively with the spring arms of the other of said supporting members, said rotor being fabricated from an insulating material and having a plurality of through contacts spaced therealong in transverse alignment with said spring arms respectively, some of said spring arms being bent in a clockwise direction and others in a counterclockwise direction relative to said rotor so that at a given position of said rotor some of said spring arms are in normally opened condition and others of said spring arms are in normally closed condition relative to said rotor contacts.

13. The combination according to claim 12 wherein each end of said rotor contacts and each of said spring arms is provided with rounded contact surfaces so that said spring arm contact surfaces wipingly engage said rotor contact surfaces in over-center fashion as said rotor is revolved.

14. The combination according to claim 13 wherein said rotor is provided with a pair of diametrically opposed longitudinally extending arcuate surfaces lying between said rotor contact ends, and said spring arm contact surfaces are bearingly engageable with said arcuate surfaces to modify said over-center action.

15. The combination according to claim 12 wherein said end plates are provided with aligned aperture means for insertion of an adjustment tool or the like, and a tubular extension is secured to each of said end plates in communication and in alignment with said aperture means so that said tool cannot be angulated to engage electrical components of said switch upon insertion through said aperture means.

References Cited UNITED STATES PATENTS 2,421,881 6/1947 Heasty 200155 2,945,096 7/1960 South 20025 3,015,002 12/ 1961 Laviana. 3,206,563 9/1965 Locke et 211. 3,359,392 12/1967 Heath.

ROBERT K. SCHAEFER, Primary Examiner I R. SCOTT, Assistant Examiner US. Cl. X.R. 

